Automatic vending machines have been in use for a long time. However most vending machines provide either hot or cold beverages, but not both. Other machines dispense only one type of hot or one type of cold beverage. In order to satisfy the desires of consumers, it is necessary to supply vending machines for many types of beverages, including coffee, Sanka, tea, hot chocolate, soup, and cold drinks, both carbonated and non-carbonated.
In order to vend a wide variety of beverages, the procedure used in the past was to install at least two separate machines, one machine selling only cold beverages and another selling only hot beverages. While this solution provides the required variety, vending machines are unwieldy and expensive to operate. Two machines occupy twice the amount of space as one such device. The cost of operating and maintaining two machines is clearly greater than in the case of one machine. And two machines require two separate support systems, which further increases the expense. With the large increases in the prices of such machines, the use of more than one machine becomes an expensive undertaking.
It is therefore desirable to combine the vending functions of two or more machines into one. However, problems arise due to the multiplicity of control circuits required to provide adequate service to the customer. For example, it is necessary to give the customer the choice of adding cream and/or sugar to coffee, but it is also important not to allow cream and sugar to fall into a cup containing cold soda. Furthermore, each type of hot beverage must be stored and prepared separately from the other types of hot beverages, and the same applies to cold beverages. Soup must not be mixed with coffee, and cola should not appear in root beer. At the same time, the beverage selecting mechanism should be sufficiently flexible to allow a selector button to be re-designated as a hot or cold beverage selection, depending upon the vending needs of the user. The latter flexibility requirement tends to conflict with the requirement of separation of functions, and is a major problem in constructing such a combination vending machine.